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cotter pin

cotter pin

2 7.4
A metal pin with split ends that you put through a hole and bend apart to hold parts together
  • noun
  • /ˈkɒtər pɪn/
  • Specialized
translation icon : pasador
  • I thought about drilling holes through the frames and seatposts and using bolts or cotter pins to hold the seatposts in place.
  • pulling a cotter pin

Examples

  • Improve the parts individually, one available at a time, being careful to successfully retain all the parts you will likely need to put everything back together, including all bolts, bearings, and cotter pins.

    Blog text (6)
  • Remove the cotter pin from the tie rod end and pop the tie rod end out of the steering arm.

  • - It's a cotter pin.

  • - Down to the last cotter pin.

  • "For the loss of a cotter pin," he mourned, "the young men have died."

    Fiction book (1999)
  • Val eases the cotter pin from the nose of one of the bombs.

    Fiction book (1990)
  • You need a cotter pin to secure the wheel assembly tightly.

  • Use pliers to install the tie rod end with a fresh cotter pin.

Synonyms

pin
vscotter pin
153 1.0

A small metal or plastic object used to attach things to cloth

is a specific split fastener secured by bending its ends
safety pin
vscotter pin
4 1.0

A small metal thing with a sharp point and a cover that holds clothes together

fastens by inserting a split metal piece and bending its ends to lock
cotter
vscotter pin
  • Specialized
2 9.9

A pin or wedge that you push through holes to hold parts together

secures parts by bending split ends after insertion
cottar
vscotter pin
  • UK
9.9

A small metal pin pushed through two parts to hold them together

secures parts by bending split ends after insertion
dowel pin
vscotter pin
  • Specialized
6.7

A small round metal or wooden rod that you put into holes in two pieces to hold them together

uses a split fastener secured by bending its ends after insertion

How Secure

rivet
  • Specialized
12 6.1
bolt
  • Specialized
42 3.8
cotter pin
  • Specialized
2 7.4
dowel
  • Specialized
5 6.5

Surface Forms

cotter pin singular
cotter pins plural

Morphology

cotter + pin

The term is a straightforward noun–noun compound: 'cotter' (a metal securing wedge/pin) combined with 'pin' (a fastener) denotes a specific type of pin used to secure parts. This compositional relation follows normal English compounding patterns, so a B1 learner who knows both constituents can readily infer the meaning.

Etymology

Cotter pin comes from its simple, physical look: a thin pin with a split end called a cotter that you push through a hole. Once it is in place you bend the split ends outward so it cannot come out, and that clear image explains why a cotter pin 'secures' or 'locks' parts together today.